class Test {
  constructor () {
    this.name = 'lee'
    this.age = 26
    this.getName = () => {
      return this.name
    }
  }
  getAge() {
    return this.age
  }
}
var t = new Test()
console.log(t.getAge())
console.log(t.getName())
console.log(Object.getPrototypeOf(t).getAge.call(t)) // t 原型对象里没有age属性，age属性需要在原来对象里找，所以需要利用call改变this指向
console.log(t.__proto__.getAge) // [Function: getAge]
console.log(t.__proto__.getName) // undefined
